1. Field of the Invention
The present general inventive concept relates to a network printing system, a network communication method to print information, and a host and an image forming device to perform network communications. More particularly, the present general inventive concept relates to a network printing system, a network communication method to print information, a host and an image forming device to perform network communications, whereby a host located in a public network can use an image forming device located in a private network having a firewall disposed therein.
2. Description of the Related Art
A network printing system is a system in which plural user terminals share one or more image forming devices through a private network, and users request operations related to image forming to the image forming devices. Such a network printing system intercepts access of an external host by using the firewall, if the access is attempted from the external host through a public network.
The firewall is equipment for protecting the image forming device connected to the network from an external invasion. The firewall permits access from inside to outside through the private network and the public network, but intercepts access by the external host from an outside to an inside through the public network. However, if the access by the external host is set to be permissible by a network manager, the firewall releases the intercept of the access by the external host and permits the access.
Accordingly, if a user intends to print a document stored in the external host by using the image forming device located in the private network in a state that the firewall is not set to permit access by the external host, the external host cannot transmit data of the document to the image forming device. That is, in the conventional network printing system, the user cannot transmit the document stored in the external host to the image forming device in the private network due to the firewall, and thus cannot have the image forming device print the document.